首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   34512篇
  免费   1300篇
  国内免费   18篇
  2019年   441篇
  2018年   609篇
  2017年   680篇
  2016年   644篇
  2015年   481篇
  2014年   537篇
  2013年   2714篇
  2012年   952篇
  2011年   1058篇
  2010年   699篇
  2009年   690篇
  2008年   964篇
  2007年   895篇
  2006年   844篇
  2005年   717篇
  2004年   675篇
  2003年   723篇
  2002年   663篇
  2001年   1244篇
  2000年   1213篇
  1999年   879篇
  1998年   406篇
  1997年   338篇
  1996年   342篇
  1995年   342篇
  1994年   342篇
  1992年   756篇
  1991年   730篇
  1990年   700篇
  1989年   648篇
  1988年   619篇
  1987年   612篇
  1986年   574篇
  1985年   660篇
  1984年   515篇
  1983年   421篇
  1982年   339篇
  1979年   507篇
  1978年   374篇
  1977年   376篇
  1976年   351篇
  1975年   443篇
  1974年   463篇
  1973年   519篇
  1972年   405篇
  1971年   337篇
  1969年   348篇
  1968年   400篇
  1967年   357篇
  1966年   402篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
41.
Suicides among older adults in the United States and Canada in the last decade have accounted for an increasing share of all suicides. In both countries the use of firearms among older adults has steadily increased. Despite these trends, little is known about the extent to which crisis centers are prepared to prevent elder suicide. A survey of AAS-listed crisis prevention centers examined the training, knowledge, and current practices relevant to elder suicide among personnel in 321 crisis prevention centers in both countries. Results revealed insufficient training, a lack of familiarity with recent suicide trends, and limited outreach to older adults.  相似文献   
42.
Cancellation tests are commonly used in the clinical assessment of visuospatial function, but there has been little study of task characteristics influencing performance. This study was designed to assess factors which affect cancellation performance. Sixteen healthy subjects sequentially performed four random-array letter cancellation tasks. The forms contained 50 and 100 stimuli and target:distractor (T/D) ratios of 1:4 and 1:9 with target letter “A” and randomly selected letter distractors. The primary performance measure was calculated as the number of correctly cancelled targets divided by the time to complete the task, corrected for accuracy. This measure revealed a strong effect of T/D ratio (p< .0001), with performance adversely affected by higher proportion of distractors. There was no effect of stimulus number. This suggests that T/D ratio should be considered in cancellation test design and interpretation.  相似文献   
43.
44.
45.
46.
47.
The token economy has been the primary model for the behavioral management of inpatient populations. However, this basically operant approach seldom emphasizes the development of cognitive-coping skills to help patients more effectively manage stressors that result in hospitalization. The Therapeutic Contract Program (TCP) is described as an inpatient-treatment strategy that is designed to help foster such cognitive-coping and self-control skills. While external structure is provided by components of this program, subprograms of the TCP have as their goal the development of internally-attributed coping skills and self-perceptions of competence. This preliminary report describes the structure of the TCP, as well as planned and in-progress measures of program participation and treatment outcome.  相似文献   
48.
49.
50.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号